1. Field of the Invention
The present invention relates to an active vibration insulator, especially, an active vibration controller for actively inhibiting the vibrations of vibration generating sources, such as vehicle engines, from transmitting.
2. Description of the Related Art
Japanese Unexamined Patent Publication (KOKAI) No. 2001-117,644, for example, discloses a conventional active vibration insulator which is equipped with an electromagnet. The electromagnet is disposed inside a so-called engine mount, and generates vibrating forces to inhibit the vibrations of engines from transmitting. Specifically, the vibrations of engines are inhibited from transmitting by controlling the turning on and off of electric supply to the electromagnet depending on the vibrations of engines.
However, the conventional active vibration insulator might possibly generate abnormal noises when turned-on electricity supply to the electromagnet is turned off.